Method for producing hydrazine

ABSTRACT

Methods are provided for producing hydrazine by irradiating ammonia from a source of radiation energy in a reaction zone. The reaction is carried out in the presence of a second material, which serves simultaneously to intercept H radical produced by such reaction and prevent the reaction thereof with the product, and as a secondary source of the product. The second material is a monohaloamine, a dihaloamine, a trihaloamine, or mixtures of all three ammonia derivatives of a single halogen.

United States Patent Pedersen 1 *Dec. 2, 1975 [54] METHOD FOR PRODUCINGHYDRAZINE 3,542,659 ll/l970 Gaussens 204/l57.l H

[76] Inventor: George C. Pedersen, 155 Hillside Drive Orchard Park 14127Primary ExaminerHoward S. Williams Notice; The portion of the term ofthis 7 Attorney, Agent, or Firm-Mandeville and Schweitzer patentsubsequent to Apr. 1, 1992, has been disclaimed.

221 Filed: June 7, 1974 [571 ABSTRACT PP 477,439 Methods are rovided forproducing hydrazine by irra- Related US. Application DataC0ntinuati0n-in-part of Ser, No. 348,536, April 6, 1973.

References Cited UNITED STATES PATENTS 2/1956 Gunning etal. 204 1571 Rdiating ammonia from a source of radiation energy in a reaction zone.The reaction is carried out in the presence of a second material, whichserves simultaneously to intercept H radical produced by such reactionand prevent the reaction thereof with the product, and as a secondarysource of the product. The second material is a monohaloamine, adihaloamine, a trihaloamine, or mixtures of all three ammoniaderivatives of a single halogen.

11 Claims, N0 Drawings METHOD FOR PRODUCING HYDRAZINE STATEMENT OF THEINVENTION This application is a continuation-in-part of copendingApplication Ser. No. 348,536, filed Apr. 6, 1973. Generally speaking,this invention relates to methods for producing hydrazine. Moreparticularly,this invention relates to an improved method for producinghydrazine from ammonia, which results in a much higher percentageproduction of the product from a specific quantity of starting materialsand a specific amount of radiation energy utilized, by incorporatinginto the reaction zone a second material which serves the dual functionof controlling the H radical produced from such reactions, thuspreventing it from reacting with the product and reducing the quantityof the product achieved; and secondly, it serves to provide anadditional source of the product itself.

BACKGROUND OF THE INVENTION As is well known, hydrazine has become avery important chemical in the last few years, because it is valuable asa component in a variety of important uses. For example, hydrazine isone of the chemicals utilized in the development of a number of newbio-chemicals. Moreover, it is one of the primary components containedin certain rocket fuels developed recently. In addition, it has becomeimportant as a reducing agent in a variety of different applications.

Because of its appropriateness in these various applications, the demandfor hydrazine has become extensive. However, it is extremely expensiveto produce in known procedures because of the difficulties in obtainingthe hydrazine product in quantities which would make the chemicalappropriate for standard commercial enterprises. That is, the percentquantity produced of the product hydrazine from the starting materialsis so small that the cost of the hydrazine is excessive for routineapplications.

STATEMENT OF THE PRIOR ART gen atom attack. That is, such reactionsresult in activated ammonia molecules which yield amino radicals (NH andhydrogen atoms. Hydrazine molecules result from the union of pairs ofamino radicals, but the yields are low because this reaction between theamino radicals must compete with the reformation of ammonia by reactionof an amino radical with a hydrogen atom and by reaction of hydrazinewith hydrogen atoms or other radicals. Such reactions are as follows:

NH, NH2-- N 14 Thus, the problem arises that in order to utilize theappropriate advantages of ionizing radiation in the production ofhydrazine, it becomes necessary to control the related H radicalproduced, so that the latter does not attack the product and bring abouta decomposition reaction thereof. Certain attempts have been made tocontrol the H radical by incorporating into the reaction zone a secondcomponent which serves as an interceptor or scavenger for the H radical.That is to say, compounds are included in the reaction zone initially,which are capable of preferentially collecting the atoms of hydrogen orfree electrons which would ordinarily attack the hydrazine productproduced, and thus reduce yields. With such arrangements, increasedproduct yield is achieved, but still not on a basis which provides aproduct yield which is commercially advantageous on a routine basis.

SUMMARY OF THE INVENTION With this invention, by contrast, productyields of hydrazine are produced by exposing ammonia in a reaction zoneto a source of radiation energy to produce product yields having a Gvalue within the range of between about 5 and 20. The G value is themeasure of yield in terms of the quantity of radiation energy requiredto produce a particular amount of product yield. It is measured inmolecules of product produced per electron volts of energy deposited inthe samples during the reaction.

The above is achieved by incorporating into the reaction zone a secondmaterial in the manner of the prior art described above, but whichmaterial serves not only as a scavenger or interceptor" of the H radicalproduced by the decomposition reaction of ammonia exposed to radiationenergy, but which second component also serves to provide an additionalsource of product. The second component is a halogen derivative ofammonia and may be a monohaloamine, a dihaloamine, or a trihaloamine, ormixtures of the three. Preferably, it will be monochloramine which maycontain minor amounts of dichloroamine and trichloroamine. Theadditional quantities of amine radical present from the halogenderivative serve to combine with the ammoniaand effectively control thefree H radical to produce additional quantities of hydrazine product.

Whereas, it has been proposed to utilize anhydrous ammonia and chlorineto produce an intermediate reaction product or monochloramine, which inturn produces hydrazine in substantial quantities by chemical reactionof additional quantities of the ammonia in the reaction zone with thechlorine itself, the yield is not as high as desired, because of therequirement of additional quantities of ammonia in order to cause thereac tion of those additional quantities of ammonia with theintermediate monochloramine product. The applicant here has discoveredthat by providing for the addition of the haloamines to ammonia in thereaction zone initially, that amine to amine linkages are produced fromthe haloamines in the presence of a source of radiation energy while thehaloamines simultaneously provide 3 effective control of H radicalattack on the product produced.

Before describing this invention in more detail, it may be well to notethat this invention has been found applicable to the utilization of awide variety of sources of radiation energy including, for example,radiation produced by electron bombardment from a Van de Graffgenerator, the kinetic energy produced from fission fragments evolvingfrom nuclear reactions, as well as actinic radiation produced fromultraviolet radiation, X-rays and gamma rays. Radiation in the form ofelectrons is appropriate in most applications because it can be moreeasily controlled for the purposes of determining yield in relationshipto radiation energy utilized (the G value).

DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION A preferredcycle of operation for carrying out the invention, in accordanceherewith, includes selecting a reaction vessel of a size which willeffectively accommodate the volume of the combined initial reactants tobe utilized in the reaction, in accordance herewith. Generally, thevolume will be 1 to 3 times the volume of the combined reactants, andpreferably two times for liquid reactants and one time the combinedreactants for gaseous reactants. The combined initial reaction mixturewill be ammonia and a second component selected from the groupconsisting of a monohaloamine, dihaloamines, trihaloamines and mixturesof all three ammonia derivatives of a halogen. Preferably, the secondcomponent will be monochloramine with minor amounts of di and/ortrichloroamine.

The amount of the second material utilized in the combined reactionmixture initially will be within the range of between about 1 X 10 3 Xmoles/liter of the total quantity, and preferably about 0.23 moles perliter of the mixture for liquid reactants. For gaseous reactions,preferably the amount will be 2 X 10 moles/liter. The temperature in thereaction vessel prior to beginning exposure will be within the range ofbetween about 200C and 85C, and preferably about 76C for liquidreactants and about 20C for gaseous reactants. The energy utilized willbe within the range of between about 0.1 and 1.5 MEV (million-electronvolts), and, preferably, 1 MEV. The time of exposure will be within therange of between about 10 and 2,000 seconds to yield a certain applieddose to the reactants, as will be understood, and preferably about 1,000seconds for liquid reactants and 100 seconds for a gaseous phasereaction. The total dose applied is selected to cause the reaction of asignificant amount of the second component.

Whereas, what actually takes place in the reaction vessel in thepresence of the radiation energy cannot be specifically described, itcan be theorized that the monochloramine, for example, controls theliberated H radical by reactions between the two, generally expressed asfollows:

NI-I CI H NI-I Cl 4 The NH product of this reaction is reacted with afurther quantity of the NI-I Cl to produce hydrazine, and a chlorideradical according to the reaction NI-I Cl NH N H Cl The chloride radicalis then reacted with ammonia present in the reaction vessel to produceNH and I-ICl according to the reaction (5) above, and the NI-I therebyproduced is reacted with NH Cl according to the reaction (6) above.Thus, it can be seen that the reactions noted above are chain reactions,and serve to tie up the H radical to produce NH radicals and hydrazine.

Moreover, it can be theorized that the hydrogen radical can be reactedwith the NI-I CI to produce NH and I-ICl according to the reaction TheNH radical so produced is then reacted with NI-I Cl according to thereaction (6) noted above, the chloride radical produced thereby beingreacted with ammonia according to the reaction (5) noted above.

Thus, by the reactions (5) and (7) noted above, each I-I radical reactsto form one amine or chloride radical, each chloride radical reacting toform one amine radical according to the reaction (6) noted above.Accordingly, each amine radical reacts to form one molecule of hydrazineplus one chloride radical, thus repeatedly and sequentially by reactions(5) and (6) providing a chain reaction for the formation of hydrazine.

Whereas, the above theoretical discussion cannot be entirely proved, theresults achieved, in accordance herewith, of high G value yields provethat the reactions utilized herein are thermodynamically favorable, asopposed to prior art methods wherein an initial additional component inthe reaction zone was utilized only to scavenge or control the H radicalproduced in the initial reaction. With the utilization herein of thatadditional component to provide the dual function of controlling the Hradical produced so as to prevent its decomposition reaction with thehydrazine product, and as a source of additional quantities of amineradical to produce additional quantities of hydrazine, more product isachieved for the same energy utilized.

As purely illustrative of the results achieved, in accordance herewith,one may note the following examples. In Example I, a liquid phasereaction takes place. It is to be understood, however, that theseexamples are being presented with the understanding that they are tohave no limiting character on the broad disclosure of the invention asgenerally set forth herein and as directed to men skilled in the art.

EXAMPLE I In this example, a representative mixture of the reactioncomponents of liquified ammonia and monochloramine was preparedaccording to the procedures reported by Robert G. Laughlin,Chemitur-Zig/Chem. Appartur, 92, 1968, ll, pages 385-387. The reactionvessel had a volume of about 200cc. and the volume of the combinedsolution prepared as described above was about cc. The original solutiontested at 0.23 i 0.06 moles per liter as NI-I Cl. It should beunderstood product produced in the first exposure was 0.24 i003 molesper liter after the first irradiation, and 0.16 i 0.03 moles per literafter the second irradiation.

An imprecise analysis of the lower limit of hydrazine production wasmade. In this connection, it should be understood that at least 90percent hydrazine is expected to decompose. This factor was not includedin the figures for the lower limit of hydrazine production.

The amount of product produced was 4.6 X 10 molecules and the G value asabout 0.5 using the calibration factor of X (ev/minute-micro-amps.).

As further illustrative of the results achieved with the inventionherein, one may note Example II below, in which gaseous phase reactantswere utilized.

EXAMPLE II In this example, 'a gaseous mixture of ammonia andmonochloramine was prepared according to the procedures used in ExampleI. The reaction vessel had a volume of about 50 liters. The originalsolution tested 4.2 i 0.4 X 10 moles/liter, as NH Cl. The initialsolution probably contained minor amounts of diand/or tri chloramine.

After initial preparation, the mixture was collected in the reactionvessel to a pressure of about 10 inches of water and a temperature ofabout 21C. A Van de Graff generator was utilized to produce electrons asa source of energy with a current of 100 micro amps. and an energy of 1MEV. The time of exposure was 100 seconds.

Following the irradiation, a fine white powder was noticed to besuspended in the gaseous mixture. A sample of the mixture was takenthrough a Millipore filter. The Millipore filter collected the solids(sample A) and yielded a substantially solids-free gas (sample B).Sample A contained no detectable monochloramine and 4 X 10' moles ofhydrazine per liter of sample B. Sample B contained no detectablehydrazine, but contained 2.13 i- 0.3 X 10' moles of NI-I Cl/liter.

The solids were noticed to collect rapidly on the sides and bottom ofthe reaction vessel. The reaction gas became clear within a few minutesfollowing irradiation.

6 so that it does not degrade the product produced, but also serves toprovide an additional source of product, all in the same timeperiod andwith the same quantity of energy utilized.

That is, no additional energy is required in order to provide for thisincreased yield during the same period of time as would be the case ifthe additional component served only to scavenge the H radicals, as isthe case in the prior art. Thus, the methods herein produce greatlyenhanced yields making the product more readily available as a routinecomponent for standard commercial operations. 4 7

While the methods herein disclosed form preferred embodiments of thisinvention, this invention is not limited' to those specific methods, andchanges can be made herein withoutdeparting from the scope of the Thissuggests that the collection of the solid sample A is less thanrepresentative of the actual original solids concentration. The dosebased on calorimetry was 0.47 X 10" ev. The yield as G value based oncollected sample and calorimetry dose was 2.4 molecules/100 ev of energydeposit.

As will be seen from the above examples, the process, in accordanceherewith, is effective for obtaining enhanced yields of hydrazineproduct by carefully utilizing a specific quantity of energy forproducing under the same time and temperature conditions an increasedamount of product.

Accordingly, and as will be apparent from the foregoing, there areprovided, in accordance herewith, methods for producing enhanced yieldsof hydrazine utilizing thermodynamically favorable reactions, because anadditional component is included in the reaction zone initially whichnot only serves to control the H radical invention which is defined inthe appended claims.

I claim:

1. A method for producing enhanced yields of hydrazine, the steps whichcomprise placing a quantity of a reaction mixture comprising ammonia anda second component in a reaction zone; said second component beingselected from the group consisting of a monohaloamine, a dihaloamine, atrihaloamine and mixtures of all three ammonia derivatives of a singlehalogen; exposing said reaction zone to a source of radiation energyunder time and temperature conditions effecting decomposition of saidammonia to hydrazine product and H radical, and the reaction of saidsecond component with said H radical to produce additional hydrazineproduct; and withdrawing said hydrazine product from said reaction zone.

2. A method as recited in claim 1, in which said source of radiationenergy is electrons.

3. A method as recited in claim 2, in which said exposing step iscarried out by the application of energy at the rate of within the rangeof between about 0.1 and 1.5 millionelectron volts for a period of timewithin the range of between about 10 and 2000 seconds.

4. A method as recited in claim 1, in which said ammonia reactant isgaseous ammonia.

5. A method as recited in claim 4, in which said exposing step iscarried out by the application of energy at the rate of lmillion-electron volts for seconds.

6. A method as recited in claim 1, in which said second component isselected from the group consisting of monochloramine, dichloroamine,trichloroamine and mixtures thereof.

7. A method as recited in claim 6, in which said ammonia is gaseousammonia and said second component is present in the amount of 2 X 10moles per liter of said reaction mixture.

8. A method as recited in claim I, in which said placing step is carriedout at a temperature of about 20C.

9. In a method for producing enhanced yields of hydrazine; the stepswhich comprise placing a quantity of a reaction mixture comprisingammonia and as the second component, at least one halogen derivative ofammonia in a reaction zone; said second component being present in saidreaction mixture in the amount of within the range of between about 1 X10' and 3 X10 moles per liter of said reaction mixture; exposing saidreaction zone to a source of radiation energy at the rate of lmillionelectron volt for within the range of between about 10 and 2000seconds effecting decomposition of said ammonia to hydrazine product andH radical, and the reaction of said ammonia derivative with said Hradical to produce additional hydrazine product;

11. A method as recited in claim 9, in which said halogen derivatives ofammonia are present in the amount of about 2 X 10' moles per liter ofsaid reacgroup consisting of monochloramine, dichloroamine 5 mixtureandtrichloroamine.

1. A METHOD FOR PRODUCING ENHANCED YIELDS OF HYDRAZINE, THE STEPS WHICHCOMPRISES PLACING A QUANTITY OF A REACTION MIXTURE COMPRISING AMMONIAAND A SECOND COMPONENT IN A REACTION ZINC; SAID SECOND COMPONENT BEINGSELECTED FROM THE GROUP CONSISTING OF A MONOHALOAMINE, A DIHALOAMINE, ATRIHALOAMINE MIXTURES OF ALL THREE AMMONIA DERIVATIVES OF A SINGLEHALOGEN; EXPOSING SAID REACTION ZONE TO A SOURCE OF RADIATION ENERGYUNDER TIME AND TEMPERATURE CONDITIONS EFFECTING DECOMPOSITION OF SAIDAMMONIA TO HYDRAZINE PRODUCT AND H RADICAL, AND THE REACTION OF SAIDSECOND COMPONENT WITH SAID H RADICAL TO PRODUCE ADDITIONAL HYDRAZINEPRODUCT; AND WITHDRAWING SAID HYDRAZINE PRODUCT FROM SAID REACTION ZONE.2. A method as recited in claim 1, in which said source of radiationenergy is electrons.
 3. A method as recited in claim 2, in which saidexposing step is carried out by the application of energy at the rate ofwithin the range of between about 0.1 and 1.5 millionelectron volts fora period of time within the range of between about 10 and 2000 seconds.4. A method as recited in claim 1, in which said ammonia reactant isgaseous ammonia.
 5. A method as recited in claim 4, in which saidexposing step is carried out by the application of energy at the rate of1 million-electron volts for 100 seconds.
 6. A method as recited inclaim 1, in which said second component is selected from the groupconsisting of monochloramine, dichloroamine, trichloroamine and mixturesthereof.
 7. A method as recited in claim 6, in which said ammonia isgaseous ammonia and said second componenT is present in the amount of 2X 10 5 moles per liter of said reaction mixture.
 8. A method as recitedin claim 1, in which said placing step is carried out at a temperatureof about 20*C.
 9. In a method for producing enhanced yields ofhydrazine; the steps which comprise placing a quantity of a reactionmixture comprising ammonia and as the second component, at least onehalogen derivative of ammonia in a reaction zone; said second componentbeing present in said reaction mixture in the amount of within the rangeof between about 1 X 10 5 and 3 X 10 1 moles per liter of said reactionmixture; exposing said reaction zone to a source of radiation energy atthe rate of 1 millionelectron volt for within the range of between about10 and 2000 seconds effecting decomposition of said ammonia to hydrazineproduct and H radical, and the reaction of said ammonia derivative withsaid H radical to produce additional hydrazine product; and withdrawingsaid hydrazine product from said reaction zone.
 10. A method as recitedin claim 9, in which said halogen derivatives of ammonia are selectedfrom the group consisting of monochloramine, dichloroamine andtrichloroamine.
 11. A method as recited in claim 9, in which saidhalogen derivatives of ammonia are present in the amount of about 2 X 105 moles per liter of said reaction mixture.